Molecular Environmental Sciences
Dalton Abdala's webpage
Molecular Environmental Sciences
Over the past couple of decades, advances in the geosciences field, more specifically on soil chemistry and soil fertility, have brought enhanced agricultural production and improvements in the quality of our environment. Major advances were, however, made on plant nutrition, transport of contaminants and chemical characterization of soils and plant materials relying on chemical extractions made on a macro-scale basis. Even though much progress has been achieved, many questions arisen in the past still stand devoid of an appropriate answer.
Having in mind that these limitations are not but due to the lack of appropriate analytical techniques, the remaining questions from the past together with the ones still to come evoke the need for the use of more advanced techniques that can provide more detailed information on biogeochemical processes. In light of the aforementioned, one can argue that the frontiers in geosciences for the coming decades will unquestionably rely on the knowledge of chemical, physical and biological processes taking place in soils at its more fundamental level – the atomic level.
"obtaining detailed structural information of materials at their most fundamental level -
the atomic/molecular level"
Overview of the storage ring and beamlines at the UVX, the Brazilian synchrotron facility currently in operation
Overview of Sirius, the new 3 GeV 3rd generation synchrotron facility currently being designed in Brazil
This is because the reactions that occur at the molecular/atomic scale play crucial roles in the environment as they control, to a large extent, the availability of plant nutrients, transport of pollutants, contamination in the subsurface and so forth. To foster our understanding on the intricate reactions at the interface between soils – a heterogeneous mixture of organic and inorganic compounds of varying composition and surface activity – and the bathing solution or plants roots, molecular environmental sciences (MES) have emerged. Molecular environmental scientists look for answers to complex questions like the ones commonly brought up when deciphering nature by zooming in on their smallest components: chemical reactions taking place at the scale of molecules and atoms. In this sense, synchrotron-based techniques are ideal for studying the structure of materials on the molecular scale, as it enables scientists to work out larger-scale objects.
BEAMLINES/TECHNIQUES
XRF
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X-RAYS FLUORESCENCE
Experimenters can benefit from a hard µ-X-rays fluorescence beamline, the µ-XRF, where imaging of heterogeneous materials, such as soils and other environmental samples, can be obtained. This is a technique that is particularly suited to one aimed at shedding light on the spatial distribution of the varied components making up a sample.
External link:: XRF beamline
XRD
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X-RAYS DIFFRACTION
X-ray diffraction, where functional and environmental materials are commonly analyzed can be done at XPD, XRD1 and XRD2. Synchrotron-based XRD techniques allow one to obtain diffraction patterns from sample masses on the order of 1 µg or less, with data quality (signal:noise) considerably better than the best diffraction patterns obtained from laboratory-based diffractometers. The XRD1 beamline is equipped with a tandem of 24 Mythen linear detectors, which enables one to perform fast measurements, still with high resolution due to the small pixel size of 50 mm. This diffractometer also allows for heavy sample environments such as furnaces (up to 1100 °C) and cryostats (down to 15 K). Due to this unique capability, the XRD1 beamline has attracted many national and international researchers to perform their experiments at LNLS.
External link:: XRD beamlines
IMX
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X-RAYS TOMOGRAPHY
Microtomography is available at IMX at resolution down to 0.7 µm absorption or phase-contrast that can be used for three dimensional imaging of objects such as seeds, rocks, for studying soil porosity or else.
BEAMLINES/TECHNIQUES
PGM & SXS
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SOFT X-RAYS ABSORPTION
Soft X-ray research at LNLS is conducted primarily at the PGM, SGM, SXS and TGM beamlines. At these beamlines, the energy range that one can have access ranges from 7 eV up to 5 keV, encompassing the energy ranges at which the K- and L2,3-edges of several elements of environmental relevance can be analyzed, e.g., from Carbon and Nitrogen up to Phosphorus, Sulfur and Potassium.
External link:: EUV beamlines
XAFS & DXAS
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HARD X-RAYS ABSORPTION SPECTROSCOPY
Hard X-rays beamlines giving access to absorption edges in the 4-30 keV range can be obtained at XAFS1, XAFS2, DXAS and XDS. The XAFS1 and XAFS2 beamlines are particularly suited for obtaining structural (geometry, interatomic distances and coordination environment) and electronic (electronic transitions) information on heavy metals and metalloids, such as Mn, Fe, Cu, Zn, As and Cd. As for experimenters interested in rapid kinetics of soil chemical processes, ultra-fast measurements can be performed at the DXAS beamline, a dispersive X-rays absorption beamline where real-time kinetics data can be acquired down to the millisecond time-scale.
External link:: XAFS beamlines
nano-FTIR
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NANO-FOURIER TRANSFORM INFRA RED
The infrared beamline of the LNLS (IR1) is dedicated to FTIR experiments with lateral resolution down to few tens of nanometers (nano-FTIR) in the mid-IR range. The highly intense broadband IR, up to 1000 times more intense than conventional thermal sources, is generated from both bending magnetic and edge radiation, extracted from two consecutives 1.67 T dipoles in the 1.37 GeV storage ring.
External link:: IR1 beamline
External link:: IMX beamline
